Container-forming machine



NOV- 23, 19.54 J. G. vr-:RGCBBI 2,694,965

coNTA1NER-FoRM1NG MACHINE Filed Nov. 9, 1951 s sheets-snm 1 .IN V EN TOR.

0614/7 l/ergo/ BY f Nov. 23, 1954 J. G. vERGoBBl CONTAINER-FORMING MACHINE 3 Sheets-Sheet 2 Filed Nov. 9, 1951 mmv www

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l INVENTOR. x/Q/z/v Q Ve BY HTTO/VEP' Nav. 23, 1954 J. G. VRGOBBI CONTAINER-FORMING MACHINE Filed Nov. 9, 1951 s sheets-sheet s 2,694,965 Patented Nov. 23, 1954 CONTAINER-FRMING MACHINE John G. Vergohbi, Quincy, Mass., assiguor to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts Application November 9, 1951, Serial No. 255,641

12 Claims. (Cl. 93-36.01)

This invention relates to a container-forming machine. In general, the invention has for an object to provide a novel and efficient container-forming machine which may be embodied with advantage in a packaging machine for producing the inner liners for lined containers and which may comprise an improvement in the containerforming machine illustrated and described in my copending application, Serial No. 690,368, filed August 14, 1946, and which has matured into Patent 2,577,386.

With this general object in view, and such others as may hereinafter appear, the invention consists in the container-forming machine, and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred form of the machine, Fig. 1 is a plan view of a container-forming machine embodying the present invention; Fig. 2 is a side elevation of the machine shown in Fig. l; Fig. 3 is a cross-sectional view taken on the line 3 3 of Fig. 2; Fig. 4 is a cross-sectional view taken on the line 4 4 of Fig. 5; and Fig. 5 is a cross-sectional View taken on the line 5-5 of Fig. 2.

In general, the present invention contemplates the provision of apparatus for the production of inner bags or liners adapted to be sealed for use in a container for the packaging ofV foods and other commodities. ferred embodiment of the invention, individual flat bags may be produced from a web of heat-scalable bag-forming material, and provision is made for forming the web into a strip having a closed top and open bottom and for sealsuitable for use in the packaging of dehydrated foods or the like.

In the preferred embodiment of the invention, the bagopening and transferring mechanism for transferring a flat bag onto a mandrel may comprise movable suction Y members engageable with opposed side walls of the flat In the preg ing the strip transversely and along the longitudinal bottom edge to form a series of connected bag sections.

In accordance with one feature of the present invention, provision is made for handling relatively thin and fragile heat-scalable bag-forming materials by withdrawing the web and moving the strip continuously at a substantially r constant rate through the bag-forming and heat-sealing stations and maintaining a substantially uniform pulling or advancing strain on the web and strip, thus avoiding the excessive strain on the web usually associated with the sudden start and stop of an intermittently operated bag-forming device.

In the illustrated embodiment of the invention, provision is made for severing successive bag sections during the continuous movement of the strip, the cut being preferably made adjacent one side of each transverse seal to l h form-individual open-mouth. bags closed` on one side by the folded edge and heat-sealed along two edges. In prac-V tice, the severing mechanism is arranged to travel along with the continuously moving strip at the same rate of speed as the strip during the severing operation, whereupon the severing mechanism is returned to its initial position to effect severance of a succeeding bag section.

Provision is also made for opening the at bags thus formed by bag-opening and transferring means arranged to engage opposed walls of the `bag and to separate the walls at the mouth of the bag sufficiently to enable the bag to be drawn over the forward end of a collapsed mandrel or forming block and then bodily transferring the bag onto the mandrel, the latter preferably forming part of a package-making machine for wrapping a container about the bag thus disposed on the mandrel. In the subsequent filling of the package, the extended mouth portions of the rectangularly formed lining bag may be brought together face to face and sealed to provide a hermetically sealed container forming an efficient package bag, and said suction members are arranged to be spread apart to effect separation of the side walls and opening of the bag to permit the same to be transferred over the mandrel. As herein illustrated and as illustrated and described in my copending application, Serial No. 690,368, filed August 14, 1946, now U. S. Patent No. 2,577,386, provision is made for forming a flat bag open at one end and provided with an unsealed portion forming a vent at the other end of the bag and for directing a stream of air through said vent and into the bag between the side walls thereof whereby to permit the bag to be successfully opened preparatory to transferring the same onto the mandrel. In accordance with another feature of the present invention, provision is made for sealing the vent opening during the continuous movement of the bag section simultaneously with or immediately after the bag-severing operation.

Referring now to the drawings, 10 represents a web of heat-scalable bag-forming material which may be withdrawn from a roll 12 thereof by unwinding mechanism, indicated generally at 14, and in general, in the formation of the bag the web is arranged to pass over the shaping mechanism comprising a generally V-shaped flared forming member 16 and between idle folding rolls 18,20 arranged to fold the web longitudinally to present opposed upper and lower portions of the walls of the web in contiguous engagement. Thereafter, the folded strip is arranged to pass between cooperating sealing rollers 22, 24, one or both of which may be heated by any suitable heating means, such as an electrical heating element, not shown.

In order to provide a vent opening in the bag and to project a stream of air through said opening and into the foremost bag section which is about to be transferred onto a mandrel, an air pipe 26 is arranged to extend vertically, as illustrated, between the side walls of the strip at a point adjacent the forming member 16 until it reaches a point midway between the upper and lower edges of the strip, and thereafter the pipe is extended horizontally and longitudinally of the strip between the side walls thereof. The air pipe 26 may be relatively small in diameter, as illustrated, in order to occupy a minimum space between the walls of the strip, and may terminate at a point adjacent the endmost bag section, as will be described. In order to accommodate the air pipe 26 between the strip during the forming and sealing operations, each roller 18, 20 may be provided with a grooved portion 28 arranged to straddle the pipe, and the sealing rollers 22, 24 are likewise provided with grooved portions 30 to leave an unsealed portion at the point where the pipe passes between the walls of the strip. As shown in Fig. 3, the cooperating heat-sealing rollers 22, 24 are provided with cooperating sealing areas 23 for forming the longitudinal seal, and with opposed sealing areas 2S for forming spaced transverse seals, the circumferential distance between the sealing areas 25 determining the spacing and length of each bag section so .that in operation there are formed a continuous longitudinal seal and successive transverse seals whereby to form a series of equally spaced bag sections.

The strip of bag-forming material is continuously drawn through the shaping and sealing devices by a pair of driven feed rolls 32, 34 provided with correspondingly grooved portions 36 to straddle the air pipe 26 and f to continue the vent opening in the transverse portion of the strip. The feed rolls 32, 34 are arranged to advance the strip continuously at a substantially constant rate, and when the endmost bag section is extended a predetermined distance beyond the feed rolls 32, 34, and while air is being projected between the bag walls through the air pipe 26 to facilitate opening of the bag, the opposed side walls at the forward end or mouth portion of the bag section are grasped and spread apart slightly by opposing suction cups 38 of a reciprocable bag` opening and transferring device indicated generally at 40, ar-

ranged to travel forwardly at the same rate as the strip during this portion of its cycle. After the bag walls have been spread apart slightly as described, a reciprocating cutter, indicated generally at 42 is also arranged to be bodily moved forwardly at the same speed as the strip and operates `to sever the endmost bag section from the strip, and simultaneously therewith or immediately thereafter, the air-vent opening is sealed by heat-sealing elements 44, 46 carried by and movable with the severing mechanism 42. The cut is preferably made along a line immediately to the rear of each transverse seal whereby the latter forms the end or bottom closure for the endmost bag section, and the severed portion adjacent thereto forms the opening for the mouth of the succeeding bag section thus forming individual bags open at the forward end and completely sealed at the trailing end or bottom of the bag. As illustrated in Fig. 4, the air pipe 26 terminates at a point beyond the feed rolls 32, 34 and immediately in front of the severing mechanism 42 in its maximum retracted position. After severance of the bag section from the strip, the speed of the bag-opening and transferring mechanism 40 is increased, and the mouth of the bag is spread apart further to permit the b'ag to be drawn over an expandible maiidrel 48, the latter preferably forming one of a plurality thereof carried by an intermittently rotatable spider 59 of the carton-forming machine. The reciprocal bagopening and transferring device 4) and the reciprocal cutting and sealing unit 42 are then quickly returned to their initial positions at an increased speed in time to open and sever a succeeding bag section of the continuously moving strip of connected bag sections.

As `illustrated in Fig. 5, the bag-forming iriachine may be driven through connections from a shaft 52 forming a part of the carton-forming machine, and as herein shown, a bevel gear 54 (see also Fig. l) fast on the shaft 52 meshes with a bevel gear 56 fast on a cam shaft 58, the latter being suitably journaled -in bearing members 60 attached to the machine frame. The bag-forming material is continuously withdrawn from the roll 12 by cooperating rollers 62, 64 arranged to be driven from the cam shaft 58 through connections including bevel gears 66, 68 connecting the shaft 58 to an inclined or oblique shaft 70 which in turn is connected to a horizontal shaft 72 by bevel gears 74, 76. The shaft 72 is connected by a second pair of bevel gears 78, 80 to a short shaft 82 which is connected to the lower feed-roll shaft 61 by spur gears 84, 86 to drive the lower feed roll 62. The gear 86 also meshes with a gear 83 fast on the upper feed-roll shaft 63 to drive the upper feed roll 64. The web 10 passes between the rollers 62, 64 and over a guide roll 9i) onto the V-shaped forming member 16 and between the idle folding rolls 18, 20 which are rotatably mounted in a bracket 92 attached to the machine frame.

The strip-advancing rolls 32, 34 are arranged to be continuously rotated at the same surface speed Ias the feed rollers 62, 64 through connections from the spur gear 84 lon the shaft 82, the gear 84 being connected by an idler gear 94 to a gearv96 fast on a short transverse shaft .98. The shaft /98 is connected by bevel gears .100, l102 to a horizontal shaft 164, the other end of the shaft l104 being connected by bevel gears Y106, 108 to :a vertical shaft 110 upon which the advancing roller 32 is mounted. The upper end of the shaft 110 is ,provided with a spur gear 112 meshing with a similar gear 114 fast on the upper end of the roller shaft 11S upon which the roller 34 is mounted, the strip-'advancing unit being mounted in a bracket 116 attached to the machine frame. The heat-sealing rollers 22, 24 are mounted for rotation in a bracket 118 and are also arranged to be continuously driven from the shaft 104 through bevel gears 120, 122 and spur gears 124, 126, the latter being fast on the shaft 21 carrying the roller 22. The shaft 23 carrying the roller 24 is provided with a spur gear 128 meshing with the gear 126, thus rotating the heatsealing rollers at the same surface speed as the withdrawing rollers 62, 64 and the feed rollers 32, 34.

When the strip of connected bag sections has been advanced a predetermined distance beyond the strip-advancing rolls 32, 34, the mouth portion of the endmost bag section is spread apart slightly by the opposed suction cups 38 of the bag-opening and transferring mechanism 40 arr'angedto travel along with the strip, and during this time air is projected from the pipe 26 through the vent opening into the bag to facilitate separation of the side walls by the suction cups. It will be understood that in operation, the 'suction cups are spaced from the side walls of the mouth portion, and the suction effects separation of opposed walls of the mouth and causes them to be brought into engagement with the cups, the air which is being blown between the side walls of the bag assisting such separation.

While the open-mouth portion of the bag is thus supported by the suction cups 38, the severing mechanism 42, also arranged to travel along with the strip, is operated to sever the endmost bag section from the strip, and the heat-sealing elements 44, 46 carried by the severing mechanism operate to seal the vent open-ing in the bag whereupon the suction cups 38 are spread apart during their advance to transfer the completed bag onto the collapsible mandrel 48. As herein shown, the suction cups 38 may extend from vertical pipes 130 supported in arms 132 fast upon studs 134 rockingly mounted in -a slide member 136. The lower ends of the pipes 30 may be connected together by a flexible conduit 138, and vacuum may be supplied to the suction cups through a flexible conduit 149 connected to an elongated horizontal pipe 142 leading to a cam-operated valve 144 which may be connected by a pipe 146 to any usual or preferred source of vacuum, such as a vacuum pump, not shown.

As herein illustrated, the slide member 136 is mounted for reciprocation upon a guide rod 148 supported at one end frorn the carton-forming machine and at its other lend in the bracket 116. The slide member is arranged to be maintained in an upright position by engagement of a depending portion 159 of the slide with a rectangular'guide bar 152 supported from the cartonformirig machine, as shown in Fig. 2. The lower end of each rocker stud 134 is provided with an arm 154 carrying rollers 156 arranged to cooperate with a stationary cam piece 158. The ends of the arms 154 may be connected by a spring 160 to hold the rollers against the cam piece 158.

As illustrated herein, the slide member 136 is reciprocated through connections from a cam 162 including a cooperating cam roller 164 carried by a lever 166 pivoted on a stud shaft 168. The cam lever 166 is connected by a link 169 to one of two elongated levers 170, 172 fast 0n the ends of a rocker shaft 174, and the upper ends of the levers 174), 172 are connected by similar links 175 to the sides of the slide member 136, as shown in Figs. l and 2. ln the operation of the machine. when the slide member 136 is in its fully retracted position, the suction cups 38 are disposed in spaced relation on opposite sides of the endmost bag section, and as the slide member starts forward and attains the speed of the moving strip. the vacuum valve 144 is operated to effect adherence of the bag to the suction cups. Upon severance of a bag section. Jthe speed of the forward movement of the slide member is increased and the opposed suction cups 38 are spread apart to fully open the mouth of the bag by engagement of the rollers 156 with the stationary cam piece 158, and the bag is transferred onto the mandrel. When the slide member 136 is in its fully extended position, the suction cups are opened to the atmosphere by operation of the valve 144 to release the bag from the suction cups Whereupon the slide member is quickly returned to its initial retracted position in readiness to open and transfer the next succeeding bag section severed from the continuously moving strip. As herein show, the vacuum valve 144 is provided with a pivotally mounted flapper 176 arranged to be opened and closed in timed relation to the movement of the slide member 136 by a cam 178 fast on the shaft 72 and a cooperating roller 180 carried by a lever 182, the latter having a lateral extension 183 operatively connected to the apper 176. The flapper 176 and the lever 182 are pivotaly mounted on a stud 184 secured in a bracket 186 'attached to the machine frame.

Provision is also made for controlling the air stream projected from the air pipe 26 to discontinue the stream of air after the side walls of the endmost bag section have been spread apart as described, and as herein shown, the Vertical leg of the pipe 26 may be connected by a flexible conduit 188 to the outlet of a valve 190 having an inlet connected by a pipe 1.92 to any usual or preferred source of compressed air. The valve 190 is provided with a plunger 194 arranged to be reciprocated to open and close the outlet port by a cam 196 fast on the shaft 72 and through connections including a cooperating roller 198 carrled by one arm of a bell crank 200 pivotally mounted on a stud 202 secured in a bracket 204 attached to the machine frame. The second armof the bell crank is loperatively connected to the upper end of the plunger 194 yby a link 206.

Referring now to Figs. 4 and 5, the cutting mechanism 42 for severing the endmost bag section from the strip during the continuous movement thereof comprises a pair of shear blades 208, 210 secured to the hubs 205, 207 of cam levers 209, 211 which are mounted to rock on a 'bushing 212 slidingly mounted on the guide rod 148. One end of the bushing 212 is provided with a collar 214 fast thereon and having a depending yoke portion 216 arranged to engage a grooved portion of a cam hub 218 which is slidingly mounted on a square shaft 220. The hub 218 is provided with a cam 222 arranged to cooperate with rollers 224, 226 carried by the levers 209, 211 respectively, as clearly shown in Fig. 5, and a spring 22S connected between the levers 209, 211 is arranged to hold the rollers 224, 226 against the cam 222.

The square shaft 220 .is provided with cylindrical ends and is mounted to rock in bearings 229, 230, the latter being formed in a depending portion of the bracket 116, and the square shaft 220 is arranged to be rocked by a barrel cam 232 fast on the cam shaft 58 and through connections including a cooperating roller 234 carried by one arm 236 of a bell crank pivotally mounted on a stud 238 secured in a bracket 240 attached to the machine frame. The second arm 242 of the bell crank is connected by a link 244 to an arm 246 fast on the shaft 220. A spring 248 connected to the arm 242 is arranged to hold the roller 234 against its cam.

The shear blades 208, 210 are yieldingly pressed together face to face by a spring 250 coiled about the bushing 212 and interposed between a flange 252 of the bushing and the hub 207 of the blade-carrying lever 211. The shearing unit 42 is arranged to be reciprocated in timed relation to the forward movement of the strip of connected bag sections by a cam 254 fast on the cam shaft 58 and through connections including a cam roll 256 carried by one arm of a bell crank 258 pivotally supported in a bracket 260 attached to the machine frame. The second arm of the bell crank is connected by a link 262 to one arm 264 of a two-armed lever pivotally mounted at 266, and the second arm 268 is connected by a link 270 to an extension from the collar 214 which is secured to the slidably mounted bushing 212 of the bag-severing unit 42. As herein shown, the heat-sealing elements 44, 46, the latter of which may be heated by an electrical heating element as indicated, are carried by arms 272, 274 extended from the hubs 205, 207 respectively which also carry the shear blades 208, 210 so that in operation, the unsealed portion forming the vent in the transverse seal is sealed substantially simultaneously with the severing operation.

It will be observed that the arm 170 forming a part of the linkage for reciprocating the bag-opening and transferring mechanism 40 is slotted to permit adjustment of the link 169 therein in order to adjust the throw and vary the extent of reciprocation, and the arm 264 forming a part of the linkage for reciprocating the cutting unit 42 is likewise slotted to permit adjustment of the same.

With this construction it will be seen that in operation during the forward movement of the shearing unit 42 in timed relation to the advance of the strip of bag sections, the square shaft 220 is rocked to effect rocking of the cam 222 and operation of the shear blades 208, 210 to sever the endmost bag section from the strip, and substantially simultaneously therewith the vent opening is sealed. As above described the suction cups 38 are arranged to support the forward end of the bag section with the bag walls slightly separated at the mouth portion during the severing operation, and as the bag is continuously advanced the walls of the mouth portion are further separated and the opened bag is drawn over the expansible mandrel to be shaped into rectangular form during the subsequent operation ofthe carton-forming machine. The bag-opening and transferring means 40 and the bagsevering means 42 are then quickly returned to their initial positions in readiness to operate upon the next succeeding bag section of the continuously moving strip.

From the description above, it will be seen that the present bag-forming apparatus is adapted to produce a flat bag of heat-scalable bag-forming material provided with face-to-face marginal seams which may be used-to advantagefor the inner liner of lined containers and that the present strip-feeding and bag-forming structure is particularly adapted for producing such flat lining bags of relatively thin and fragile bag-forming materials by maintaining a continuous and substantially uniform pull on the web of bag-forming material and avoiding any sudden or excessive strain on the relatively fragile web.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms Within the scope of the following claims. A

Having thus described the invention, what is claimed is:

1. In a container-forming machine, in combination, bag-forming means comprising means for continuously advancing a web of bag-forming material, means for folding and discontinuous means for transversely sealing the continuously moving web to form a strip of connected bag sections each having an unsealed portion forming a vent, a cutter, means for moving said cutter longitudinally with the advancing strip and for operating said cutter to effect severance of successive endmost bag sections from the strip during the continuous advance thereof rearwardly of the transverse seal to form'individual flat bags having open leading ends, and means operated simultaneously with said cutter for sealing the vent openings in successive bags.

2. In a container-forming machine, in combination, bag-forming means comprising means for continuously advancing a web of bag-forming material, means for folding and discontinuous means for transversely sealing the continuously moving web to form a strip of connected bag sections each having an unsealed portion forming a vent, a cutter, means for moving said cutter longitudinally with the advancing strip and for operating the cutter to effect severance of successive endmost bag sections from the strip during the continuous advance thereof rearwardly of the transverse seal to form individual flat bags each having an open leading end portion and a sealed bottom portion provided with an air vent, bagopening means arranged to engage opposed side walls of successive flat bags to spread them apart, and means operated simultaneously with said cutter for sealing the vent openings in successive bags.

3. In a container-forming machine having, in combination, a plurality'of expansible mandrels, bag-forming means comprising means for continuously advancing a web of bag-forming material, means for folding and discontinuous means for transversely sealing the continuously moving web to form a strip of connected bag sections each having an unsealed portion forming a vent, a cutter, means for moving said cutter longitudinally with the advancing strip and for operating the cutter to effect severance of successive endmost bag sections from the strip during the continuous advance thereof rearwardly of the transverse seal to form individual ilat bags each having an open leading end portion and a sealed bottom portion provided with an air vent, reciprocable bag-opening and transferring means for opening and transferring successive bag sections onto successive mandrels including means arranged to engage opposed side walls of successive at bags to spread them apart, means operated simultaneously with said cutter for sealing the vent openings in successive bags, and means for operating said opening and transferring means to effect opening of successive bags immediately prior to the severing operation and for thereafter transferring successive bags onto successive of said expansible mandrels.

4. In a container-forming machine having, in combination, a plurality of expansible mandrels, bag-forming means comprising means for continuously withdrawing and advancing a web of bag-forming material from a supply thereof, means for folding the web longitudinally to form a U-shaped strip, means for sealing the strip transversely at spaced intervals andV along the open longitudinal marginal edge to from a series of connected bag sections during the advance of the strip, each bag section having an unsealed portion forming a vent in said transversely sealed portions, a cutter, means for moving said cutter longitudinally with the advancing strip and for operating the cutter to effect severance of successive endmost bag sections from the strip during the advance thereof to form individual flat bags each having an open mouth portion and a sealed bottom portion provided W l with an air vent, reeiprocablebag-opening means cooperating with said bag-forming means and arranged to engage opposed side walls of a flat bag to spread them apart during the advance of the strip, means for directing a stream of air through said vent and between the side walls of the bag to facilitate separation thereof during the opening operation, means for operating said bag-opening means to eifect opening of successive bags immediately prior to the severing operation, and means carried by and operated simultaneously with said cutter for sealing the vent openings in successive bags, said bag-opening means being movable to effect transfer of successive bags onto successive of said expansible mandrels.

5. A container-forming machine as defined in claim 4 wherein the sealing means for forming the bag sections comprises a pair of cooperating heat-sealing rollers.

6. A container-forming machine as defined in claim 4 wherein the withdrawing and advancing means com prises a pair of withdrawing rollers and a pair of feed rollers, and wherein the sealing means for forming the bag sections comprises a pair of cooperating heat-sealing rollers disposed intermediate the withdrawing rollers and the feed rollers, and means for driving all of said rollers to effect a substantially constant and uniform advancing strain on the web of bag-forming material.

7. A container-forming machine as dened in claim 4 wherein the cutter comprises a pair of shear blades and wherein the vent sealing means comprises a pair of cooperating heat-sealing elements carried by said shear blades.

8. A container-forming machine as delined in claim 4 wherein the cutter comprises a pair of shear blades, and means for operating said blades during the forward travel of their reciprocable movement to effect severance of a bag section from the strip when the cutter attains a forward speed equal to the advancing movement of the web.

9. A container-forming machine as defined in claim 4 wherein the means for directing a stream of air through said vent includes an air pipe extending between the walls of the strip and through said unsealed portions, and a valve for controlling the air stream.

10. A container-forming machine as defined in claim 4 wherein the bag-opening means includes opposed suction cups, a valve for controlling the suction, and means for operating the valve.

l1. A method of. forming individual bags and transferring the same onto successive mandrels which ncludes the steps of continuously advancing a web of bag-forming material, folding the web longitudinally to form a U-shaped strip, sealing the web longitudinally along the open marginal edge and forming interrupted transverse seals at spaced intervals to form a series of connected bag sections each having a vent opening therein, engaging and opening the mouth of the endmost bag section while directing a stream of air through the vent and between the side walls of the bag section to facilitate opening thereof While the strip is advancing, severing the strip adjacent the rear edge of successive transverse seals to form individual bags, sealf ing said vent openings substantially simultaneously with the severing operation, and transferring successive bags onto successive mandrels.

12. In a container-forming machine, in combination, an expansible mandrel, bag-forming means comprising continuously operated means for forming a at bag having an open mouth portion and a sealed bottom portion provided with an air vent, reciprocable bag-opening and moving means cooperating with said bag-forming means and arranged to engage opposed side walls of the at bag to spread them apart and to move the bag forwardly toward the mandrel, means for directing a stream of air through said vent and between the side walls of the bag to facilitate separation thereof during the opening operation, reciprocable sealing means arranged to travel forwardly at the same speed as the moving bag for sealing said vent after the bag is opened, and means thereafter transferring the bag onto said mandrel.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,014,227 Conti Sept. 10, 1935 2,103,390 Salsberg Dec. 28, 1937 2,125,758 Waters Aug. 2, 1938 2,301,771 Billeb Nov. 10, 1942 2,428,837 Denton Oct. 14, 1947 2,446,798 Vergobbi Aug. 10, 1948 2,467,879 Billeb Apr. 19, 1949 2,577,386 Vergobbi Dec. 4, 1951 

